You can put any engine in there!
Study the engine mounting (stock) with the engine removed is easier but if you drive it that would be a problem (lol).
Is the Mercedes a framed car or a uni-body car? This will make a difference in how you design your mounts or what you can adapt to use. check the weight of what your pulling and what you want to go in, if they're close you should place the sbc in the same place the the mercedes motor came out of. I have done motor swaps on dozens of cars and trucks.... i'm putting a big block Buick in a 51 gmc truck right now.
take some pic's and send them in we'll figure out something.
look up "engine adapters" on the web, you'll find a bunch.